Deciduous is a designation indicating a plant sheds its leaves at the end of the growing season. The term is used primarily in reference to trees and shrubs, in contrast with those that are evergreen.. It is pronounced dih-SIJ-oo-uhs. To remember what deciduous means, try relating it to the word, decadent..
viscosity. n, pl-ties. 1. the state or property of being viscous. 2. (General Physics) physics. a. the extent to which a fluid resists a tendency to flow. b. Also called: absolute viscosity a measure of this resistance, equal to the tangential stress on a liquid undergoing streamline flow divided by its velocity gradient. It is measured in newton seconds per metre squared.
Viscosity, by definition, is an oils resistance to flow and shear. It is the single most critical physical property of the oil as it affects both the wear rate and the fuel efficiency. Water is a low viscosity fluid; syrup is a high viscosity fluid. With oil, like syrup, as you increase the temperature, the viscosity lowers, meaning it flows faster, or more easily. The most common unit of measure for viscosity is the Kinematic viscosity and this is usually quoted in data sheets at 40C and 100C.